I. nounEtymology: Middle English levain, from Anglo-French levein, from Vulgar Latin *levamen, from Latin levare to raise — more at leverDate: 14th century1.a. a substance (as yeast) used to produce fermentation in dough or a liquid; especiallysourdoughb. a material (as baking powder) used to produce a gas that lightens dough or batter
2. something that modifies or lightens
II. transitive verb(leavened; leavening)Date: 15th century1. to raise (as bread) with a leaven
2. to mingle or permeate with some modifying, alleviating, or vivifying element; especiallylighten<

leaven — ► NOUN 1) a substance, typically yeast, added to dough to make it ferment and rise. 2) an influence or quality that modifies or improves something: John s humour was the leaven of his charm. ► VERB 1) (usu. as adj. leavened) cause (dough or… … English terms dictionary

Leaven — Leav en, n. [OE. levain, levein, F. levain, L. levamen alleviation, mitigation; but taken in the sense of, a raising, that which raises, fr. levare to raise. See {Lever}, n.] 1. Any substance that produces, or is designed to produce, fermentation … The Collaborative International Dictionary of English

leaven — Yeast, added to dough. In the Bible leaven had two incompatible significances: as fermented dough left over unbaked from a previous batch it was added to cause further fermentation. It could therefore be regarded either as a living substance… … Dictionary of the Bible

leaven — n. & v. n. 1 a substance added to dough to make it ferment and rise, esp. yeast, or fermenting dough reserved for the purpose. 2 a a pervasive transforming influence (cf. Matt. 13:33). b (foll. by of) a tinge or admixture of a specified quality.… … Useful english dictionary